A New Era of Moon Exploration

In my latest essay for The New Yorker, I explore why the moon is so busy these days, and what that means for life on Earth.

On February 22nd, a robotic lander named Odysseus touched down on the sun-washed highlands near the south pole of the moon. It was the first time since the Apollo 17 mission, fifty-two years ago, that an American spacecraft had landed gracefully on the lunar surface. And yet NASA hadn’t designed or built Odysseus; it was renting space onboard. Intuitive Machines, a relatively small aerospace firm based in Houston, was responsible for the lander, which launched atop a SpaceX rocket. The event was historic not just because it signalled a return to the moon but because it was the first time that a private company from any country had landed a spacecraft there. It won’t be the last: Odysseus marks the beginning of a new, relentless, and open-ended campaign of robotic and crewed lunar exploration. The program is called Artemis.

Read the rest here.

Earth's First Cookbook

My latest for the New Yorker was seven years in the making. I first covered the OSIRIS-REx mission when it launched in 2016, for the Week. The following year, I embedded with the team for the Earth gravity assist, and wrote about it for the Atlantic. In 2018, I was also with the team for the spacecraft’s arrival at the asteroid Bennu, which I covered for Scientific American. And now, for the New Yorker, the return of the sample to the Utah desert, and the opening of the capsule in Houston, Texas. It begins:

On a brisk day in February, 2004, Dante Lauretta, an assistant professor of planetary science at the University of Arizona, got a call from Michael Drake, the head of the school’s Lunar and Planetary Laboratory. “I have Lockheed Martin in my office,” Drake said. “They want to fly a spacecraft to an asteroid and bring back a sample. Are you in?”

Read the rest here.

What the Webb Will Show Us Next

For The New Yorker, I interviewed the astrophysicist Dr. Jane Rigby, senior project scientist of the James Webb Space Telescope. Here is a snippet:

What gaps in science do the J.W.S.T.’s unique capabilities fill?

J.W.S.T. works in the infrared. It was designed to see the light from the universe that is totally invisible to Hubble, which sees primarily in the optical and ultraviolet. About the “bluest” light that J.W.S.T. can see is the shade of red wine, and then it goes redder from there.

Because of the big bang, space is expanding—not just stuff in space but the fabric of space itself. And the light that we see from distant objects has actually been stretched by the expansion of the universe as well. That causes light from those distant objects to get stretched to longer wavelengths. It gets shifted to the red, to lower energies.

It’s just really cool that we can see almost to the end of the universe, right? We can do that because that light only travels so fast: the speed of light. We are studying galaxies whose light has been travelling for more than thirteen billion years. The universe is only about 13.8 billion years old! Those are the baby pictures of literally everything, and, in particular, of the baby galaxies that would have turned into mature galaxies like our Milky Way.

You can read the rest here.

Image credit: NASA, ESA, CSA, STScI, Klaus Pontoppidan (STScI)

Department of Survival

Image credit: The New Yorker

In a special digital issue of The New Yorker for the week of April 24, I have a story about NASA’s failure on the methane emission detection issue, and how NGOs have taken it on themselves to pick up the slack. A snippet:

When his phone rang, Berrien Moore III, the dean of the College of Atmospheric and Geographic Sciences at the University of Oklahoma, was fumbling with his bow tie, preparing for a formal ceremony honoring a colleague. He glanced down at the number and recognized it as NASA headquarters. This was a bad sign, he thought. In Moore’s experience, bureaucrats never called after hours with good news.

Read the rest here.

The Asteroid Killer

For The New Yorker, I write about NASA’s efforts to stave off doomsday from above.

On the evening of September 26th, Elena Adams, the lead engineer for NASA’s asteroid-smashing DART spacecraft, peered at the data streaming to her computer console in mission control, at the Johns Hopkins University Applied Physics Laboratory, in Laurel, Maryland. Some forty other engineers were crammed into the room with her, sitting at rows of similar stations or gazing at large telemetry displays mounted on walls emblazoned with NASA heraldry. The DART spacecraft was seven million miles from Earth; after charting a ten-month, hundred-and-one-million-mile course around the sun, it had squared up for its terminal run against an asteroid called Dimorphos. If all went according to plan, DART would collide head on with Dimorphos at fourteen thousand miles an hour, fundamentally deforming the asteroid and changing its orbit. For the first time in more than sixty years of spaceflight, our species would be not just exploring the solar system but rearranging it.

Read the rest here.

Presenting the Paperback Cover!

I am thrilled and honored to present the cover for the paperback edition of THE MISSION, which lands in bookstores on January 25, 2022! It is now available for pre-order at your local indie bookstore, or on Amazon.

NPR Interviews, and Select Others

Over the last few weeks, I’ve done scores of interviews for THE MISSION. Here are a few of my favorite, though there were many, many more, and I will add them as I find them.

NPR 1A, hosted by Jennifer White on National Public Radio. We discussed THE MISSION, Mars and Europa, creative nonfiction and literature, and a second Genesis (third, if we count the band) in our solar system. Jennifer is masterful—brilliant and quick-witted, asking one informed question and follow-up after another. Speaking with her was the thrill of a lifetime.

NPR Conversations, hosted by Dan Skinner on National Public Radio. We talk Europa, creative nonfiction, human exploration of Mars, and the politics of spaceflight. Dan is a first-rate interviewer and asked probing, lettered questions. It was an honor to join him and I hope to do so again very soon. What a pleasure this was.

Scientific American, interviewed by my friend, the inimitable author Lee Billings, wherein we discuss the state of planetary science, Mars, the future, and writing books about all this stuff.

Houston Chronicle, interviewed by Andrew Dansby, in which we discuss building tension into stories, writing with a large cast of characters, recurring motifs in a narrative, and how I (hopefully!) pulled all those things off.

Universe Today, interviewed by Fraser Cain, probably the best space blogger in the business, and one of the friendliest and most generous people I’ve ever met. (Embedded above!)

The Moon is Not Enough

I was very proud to write my first essay for the Wall Street Journal—the cover story for the weekend review. In it I call for NASA to drop the moon element of the Artemis program and go directly to Mars. The short, short version is this: Everything NASA would develop for the moon would have to be re-developed entirely for Mars; there is virtually no technological overlap. If we are going to start from zero anyway, why not go with the more ambitious, long-term self-sustaining target?

A snippet:

The idea of yoking the two destinations together may be politically appealing, but fiscal reality suggests that it will be one or the other, the moon or Mars. Congresses and presidents have often rewarded NASA’s astounding achievements with punishing budget cuts. The Apollo program was arguably the greatest engineering and exploration feat in human history, but the U.S. government treated its final missions as the end of a public works project; little was done to build on its success and hard-won institutional knowledge. At the height of Apollo’s development in 1966, NASA accounted for 6.6% of federal discretionary spending. Today, that figure is about 1.6%, a figure that has barely risen to accommodate the current lunar aspirations, let alone the exploration of another planetary system in our lifetimes.

Why shift gears and make Mars the priority? NASA estimates that just landing on the moon again—not building a base there—will cost $30 billion and says that lessons learned on the moon can be applied to future Mars plans. Broadly speaking, this is true, in the way that Antarctica and the Mojave are both deserts, and survival skills cultivated in one might help in the other. But the tools necessary to do anything useful in the two environments are very different and require, for the most part, very different technologies—including, crucially, an entirely different landing vehicle to navigate the Martian atmosphere.

Read the rest here.

The New Yorker

This story for The New Yorker was almost a year in the making. In it, I offer an insider account of of the fabled mission development teams at NASA Jet Propulsion Laboratory, Team X and the A-Team, and tell the story of the 2019 Planetary Science Summer Seminar, the NASA “bootcamp” for planetary scientists who wish to learn how to plan missions to other worlds. A snippet:

… Two years later, at the Jet Propulsion Laboratory, in Pasadena, California, an astronautical engineer named Randii Wessen stood before a wall-sized whiteboard in a room called Left Field. Facing him were eighteen researchers—planetary scientists, astrophysicists, engineers—most in their mid-twenties, all graduate students or postdocs. Bald, bearded, and trim at sixty-one, Wessen worked on the Voyager and Cassini space probes. He is now the lead study architect of J.P.L.’s so-called A-Team—a group in charge of early space-mission concept planning at the lab’s Innovation Foundry. (The team is named both for the discipline of mission architecture and for the nineteen-eighties TV show about a crack team of do-gooding mercenaries.) No two of the hundreds of thousands of identified objects in the solar system are exactly alike; each must be explored according to its own characteristics. Successful missions, therefore, emerge from the spot where the proved and the fantastic intersect. The best way to explore Io, Jupiter’s volcanic moon, could be an orbiter, but it could also be a lava boat. Often, these so-crazy-they-might-work solutions begin on Wessen’s whiteboards.

Read the rest here.

Moons of Earth and Saturn

The New York Times has kept me busy of late. In the special section commemorating the fiftieth anniversary of the Apollo 11 moon landing, I had two pieces: one on the future of the American astronaut corps, and another on the haunting restoration of the Apollo Mission Control at NASA Johnson Space Center. Another piece I am particularly proud of is the announcement of a mission to Titan, the mysterious moon of Saturn, and the only place in our solar system other than Earth with standing liquid seas.

Image credit: The New York Times

NASA Announces New Dragonfly Drone Mission to Explore Titan
(The New York Times)

Because of the nature of its atmosphere, Titan is a very Earthlike place. Chemically, it is much like our world’s primordial past. The surface pressure of Titan is one-and-a-half times the surface pressure of Earth, and the same sorts of interactions between air, land and sea take place. Titan thus has familiar geology. Methane on Titan plays the role that water plays here. Its methane cycle is analogous to Earth’s water cycle. It has methane clouds, methane rain and methane lakes and seas on the surface.

“There’s going to be a tremendous change in the fabric of how we see Titan as a world,” said Dr. Ralph Lorenz of Applied Physics Laboratory, the Dragonfly project scientist in an April interview. He predicted that features of Titan will be, “recognizable, but different in flavor from what you see on Earth and Mars.”

That might include the things that wiggle. Complex organic molecules fall from its atmosphere onto the surface of Titan, gather over long periods of time and can be processed further. If cryovolcanoes erupt on Titan’s surface, as data from the Cassini spacecraft suggests, the organic material can mix with liquid water. Sunlight, at the same time, drives the moon’s photochemistry, introducing energy to a system primed for life.

NASA Reopens Apollo Mission Control Room That Once Landed Men on Moon
(The New York Times)

Apollo mission control had been abandoned in 1992, with all operations moved to a modernized mission control center elsewhere in the building. Center employees, friends, family — and anyone, really, who had access to Building 30 — could walk in, take a seat, take a lunch break and take pictures.

While they were there, they might take a button from one of the computer consoles. Or a switch or a dial, anything small — a personal memento from an ancient American achievement. The furniture fabric and carpet underfoot grew threadbare. The room was dark; none of the equipment had power. Wires hung where rotary phones had once sat. The giant overhead screens in front of the room were damaged, and the room smelled of mildew. Yellow duct tape held carpet together in places.

“You knew it wasn’t right — you just knew,” said Sandra Tetley, the historic preservation officer at the Johnson Space Center. “But it was not a priority. We are an organization that’s moving toward the future, so there is not a budget to do things like this.”

The project began in earnest six years ago. The anniversary loomed, and that was the catalyst to fix up mission control, and to do it right. “We wanted to meet a high standard to restore it, and we were able to meet this 50th anniversary,” Ms. Tetley said.

As New Space Race Beckons, Astronauts Face Identity Crisis
(The New York Times)

Christopher Ferguson trains from 8 a.m. to 8 p.m. at NASA’s Johnson Space Center in Houston. A recent day for him was typical: five hours in a launch simulation with the mission operations team. He trained alongside Sunita Williams, herself a two-time space flier and veteran of the space station.

Halfway through the session, the two swapped roles, preparing for situations that might arise on an actual mission. The balance of the day was spent planning timeline management when inserting a crew into a rocket, so that when the hatch closes, all the right things are on the inside, and all the right things are on the outside.

The difference between Mr. Ferguson and Ms. Williams is that Mr. Ferguson does not work for NASA. He works for Boeing and will fly on the first crewed mission of Starliner. Boeing and SpaceX are part of Commercial Crew, a NASA-supported program that has tasked American companies with building spacecraft capable of carrying astronauts to the space station. NASA has relied on Russia’s space program for launching astronauts since the last shuttle returned to Earth in 2011.

Pluto as Planetary Coming of Age

This composite of enhanced color images of Pluto (lower right) and Charon (upper left), taken by NASA's New Horizons spacecraft on July 14, 2015, highlights the wide range of surface features on the small worlds. Working with the New Horizons mission team, the International Astronomical Union (IAU) has approved the themes to be used for naming the surface features on Pluto and its moons. (Credit: NASA/JHUAPL/SwRI)

Kirby Runyon cuts the figure of an astronaut, and you just know that he would be helpful in a bar fight, but you also get the impression that he would defuse things for you before it got that far. He is a young man and a newly-minted Ph.D., and with an abstract submitted to the Lunar and Planetary Science Conference late last March, stepped into a white-hot spotlight with an international audience. He and one of his co-authors, Alan Stern, the principal investigator on the New Horizons mission to Pluto, have taken a swing at the question of planethood.

Runyon’s definition of a planet is a single sentence in length: “A planet is a sub-stellar mass body that has never undergone nuclear fusion and that has enough gravitation to be round due to hydrostatic equilibrium regardless of its orbital parameters.” In other words, a planet is a ball in space that’s not a star. That means, yes, Pluto is a planet. It also means that the Moon is a planet. Europa is a planet. Ganymede is a planet.

In comparison, the newly-established definition of a planet by the International Astronomical Union states: “A planet is a celestial body that is in orbit around the Sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and has cleared the neighborhood around its orbit.” In this regime, were Ganymede knocked from orbit around Jupiter and into orbit around the Sun, it would still be Ganymede, but might suddenly, according to the IAU, be a planet. At an instinctive level, this feels wrong, like saying that if a dog climbed onto a bookshelf, it would then be a cat. The astronomy view categorizes a planet based on what it orbits. Runyon’s assertion is that a planet should be defined by what it is.

What imbues Runyon’s definition with resilience is that it doesn’t seek to somehow overturn that of the IAU, and he has no intention of submitting it to the IAU for consideration. “If certain types of astronomers want to have an orbital dynamic definition of a planet,” he says, “and that’s useful to them, fine. But most scientist who study planets are more aligned now with the geosciences than they are with astronomical scientists. And that definition of ‘planet’ just isn’t useful to us. It doesn’t help us communicate our ideas.” Informally, planetary scientists have always called all sorts of bodies in space “planets.” But formally, too, in peer-reviewed literature, technical moons are called planets. Runyon lists scores of such references made both before and after the IAU redefinition.

This is in part about the coming of age of planetary science. It is a young field, a single generation old, the plucky upstart once the exclusive domain of physics, then of astronomy, but whose constituent sciences now include geology, chemistry, and biology. Mars was once something you look up at, a dot in the sky. Celestial. Now it’s something you look down on from orbit, or across from the surface. It’s terrestrial. Geophysical.

“Carl Sagan said, ‘In science there are no authorities; at most, there are experts,’” Runyon tells me as we talk outside the convention center where he presented abstract. This isn’t a heated argument, and he counts Mike Brown, the famed “Pluto Killer,” as a friendly correspondent. Let the astronomers do what they want, he explains brightly, but leave us—i.e., geologists—out of it. The concept isn’t even unique. “To astronomers studying the composition of stars and nebulae, especially stars, they call anything heavier than element number two―anything heavier than helium―a metal. That’s just a convenient word for them. No one’s fighting about this,” says Runyon. “They know what they mean when they say metal, and it’s different from the common definition. You take the spectra of stars, and you see there’s oxygen and nitrogen and argon in stars’ atmospheres, you call that a high metallicity star. And that’s fine. Metallurgists aren’t fighting them over the word metal.”

Kirby Runyon presents his research on Martian sand sheets. (Credit: Lunar and Planetary Institute)

This matters beyond the arcane world of scientific abstracts and poster sessions. Very rarely does a scientific debate spill into the public sphere and draw not only keen interest, but steely opinions. Evolution, certainly. The age of the Earth in some religious circles. But you don’t often see finger-pointed assertions over scientific nomenclature. The Washington Post doesn’t give a thousand words to disagreements over the precise definition of “suevites” (a type of rock formed during impact events) though scientists do debate its usage. This matter of Pluto, however, is both consequential and easily understood. Everyone has their own take on whether it is a planet.

Under Runyon’s definition, there are at least 110 planets in the solar system. This seems at once absurd, but resolves into something very interesting. He explains that the idea of planets being something you must memorize is a pointless exercise. Memorizing the periodic table of elements doesn’t make one a chemist. But just as the table itself is elegant and informative, plot all the planets on a table and you get something equally elegant. Terrestrial planets, gas giant planets, ice giant planets, dwarf planets, exoplanets, each arranged and subgrouped with common characteristics. Europa so plotted might be categorized as an icy dwarf satellite planet.

And suddenly, rather than rote memorization, Mercury, Venus, Earth, and so on, you have an ambitious and quite possibly tectonic effect on education. Rather than eliminating things to learn―Pluto itself has been rendered ontologically unsound since the IAU announcement, disappearing not only from textbooks but also consumer goods and media―you have the introduction of worlds that rarely appear in the classroom, Makemake, Mimas, Miranda and more. The conversation about Pluto has arguably been a net positive for the public, whose idea of the solar system is too often limited to plastic beads on wires circling a light bulb.

An invested public with a robust science education is as important as ever before. Even with our pedestrian terrestrial political problems, it’s a good time to be a human being. We stand on a precipice of sorts, in which asteroids, planets―even stars―are accessible not only by scientists with instrument-laden spacecraft, but soon by the working man and woman. One easily imagines a real future in the lifetimes of our children in which “planet” relates not to hydrostatic equilibria or accretion disc formation, but by something inherently more utilitarian. Planet will be a shorthand for something vaguely accessible by humans and our tools for long durations. Somewhere useful. Somewhere with a horizon commensurate to that which the human mind has evolved to expect. Can I drive a shovel into the body and pull up raw materials? In plain science fiction terms, can I land my spaceship on it? Is it round and can I fly my gas mining barge through it?

In both the very short term and very long, what is or isn’t a planet is not particularly important. In the middle, however, in our present-day future in which dot-com billionaires want to put people in space, and not in capsules of three, but transports of hundreds, and they say this with authority and are investing the capital to make it a reality, suddenly “planet” is a word due to be handed back to the people. Given a better spacesuit, if I lived on Titan or Mars, is there a measurable difference in bodies? This land is your land.

Q&A: Margaret Hamilton, Who Landed the First Man (and Code) on the Moon

Though you might not recognize her name, you know Margaret Hamilton’s work, and you quite possibly know her face. She led the team responsible for the on-board flight software for the Apollo command module and lunar module. A black-and-white photograph of Hamilton standing next to a stack of code has reached iconic status, for reasons obvious: here is a woman pioneering the field of computer science at a time when the discipline was almost exclusively male; a laboratory director of software engineering before “software engineer” even existed as a job title; and an achievement to her name that defies comparison with any other human endeavor.

She didn’t stop at landing astronauts on the moon. She contributed also to Skylab, the first American space station, and to the space shuttle. In 1986, she founded Hamilton Technologies, Inc., a software development firm. Last year, she was awarded the Presidential Medal of Freedom for her work on the Apollo program and for her contributions in the field of computer science to “asynchronous software, priority scheduling and priority displays, and human-in-the-loop decision capability, which set the foundation for modern, ultra-reliable software design and engineering.”

A new picture book about Hamilton was published last month by Knopf Books for Young Readers. Written by Dean Robbins and illustrated by Lucy Knisley, Margaret and the Moon recounts Hamilton’s story and brings children to the harrowing landing of the Eagle. Computer science doesn’t come immediately to mind as a rich field from which children’s literature might grow, and yet Robbins and Knisley deftly tell a story that is at once moving and exciting. It is a testament to the skill of the author and illustrator that the book will be for many readers the first biography they ever read, an early introduction to the Apollo program, and an inspiring story of how science and engineering are done — and the book excels at all three.

In an interview by email, Hamilton tells me about her journey to the Apollo program, equality in STEM, and her contributions to the computer science discipline. It has been edited lightly for length and clarity.

Margaret Hamilton with her code (Credit: MIT Museum)

What were the circumstances of the famous photo of you standing next to that towering stack of code?

MHH: The photo was part of the information that MIT provided to the news media during the time of the Apollo 11 mission. The following was excerpted from a description of the photo in an MIT document: “Taken by the MIT Instrumentation Lab photographer in 1969…Margaret is shown standing beside listings of the software developed by her and the team she was in charge of, the Lunar Module (LM) and Command Module (CM) on-board flight software team”.

Each listing in the stack of listings contained Apollo guidance computer source code. For every mission there were two listings; one for the command module and one for the lunar module. Two of the listings were for Apollo 11, one for the Apollo 11 command module and one for the Apollo 11 lunar module. Other listings in the stack contained source code for future “to be” missions (e.g., Apollo 12, Apollo 13…) that we had been working on concurrently along with the source code for Apollo 11.

Is the Apollo program something that pursued you, or did you pursue it? In other words, how does one join the most ambitious engineering endeavor in human history?

MHH: At the time, I was working at MIT’s Lincoln Labs on the Semi-Automatic Ground Environment air defense system, developing radar registration surveillance software for detecting potential enemy planes, on the first AN/FSQ-7 computer (the XD-1). I had always planned to attend graduate school at Brandeis and major in abstract math, but I got sidetracked. Sometime within the 1963–1964 timeframe, I heard the news that MIT had received a contract from NASA to develop the software for “sending man” to the moon, and that MIT was looking for people to work on this project. I immediately called MIT to see if I could be involved in what sounded like the opportunity of a lifetime. Within hours, I set up interviews with two project managers at MIT. Both of them offered me a position on the same day as the interviews. I did not want to hurt anyone’s feelings, so I told them to flip a coin to decide which group would hire me — hoping for the project manager to win the coin toss, who, in the end, did win. Fortunately, that is what happened, and I was on my way.

There is a greater effort today to correct the gender imbalance in the fields of STEM. What advice would you give to aspiring scientists and engineers?

MHH: The type of experience and education one has before entering the fields of STEM as well as other fields is key. I have found it helps to have both a “streetwise” experience and a formal education. From a streetwise perspective, the more jobs a young person has (and the more varied), the better prepared one is for going out into the world. Learning how to work with and getting used to being around different kinds of personalities and challenges helps one to have the flexibility needed to understand others, and to deal with the unexpected. It provides a better foundation from which to make career choices, including who you choose to work with and for whom you choose to work.

Regarding the formal part of education, one would of course want to take courses directly related to the particular field of STEM of interest (e.g., computer science). But, it is also important to learn and be around other kinds of things like music, art, philosophy, history and formal linguistics; any of which could help improve one’s being an excellent problem solver; and to have a more global perspective on things. The ultimate goal is learning how to think.

Women cannot be expected to solve the gender imbalance problem alone — especially on an individual-by-individual basis. Too often it is the symptoms of the problem that are being addressed by well-meaning efforts today, when the real problem has been and still is our culture. Things are still being done (and accepted as such) out of ignorance. It is not uncommon for an organization to pay women lower salaries than men for the same position, and to relegate women to the lower positions in an organization. And if not, women often have to work or fight harder than their male counterparts to be an exception. Most would agree that the STEM fields are still dominated by men; that discrimination does exist. In fact, some things seem to have gone backwards and are more difficult now than they were in the sixties. Some ways in which discrimination manifests itself can be quite different today — especially now that we have the internet.

Unfortunately, various types of communication over the internet can serve as convenient places to “hide” in, encouraging “faceless,” pervasive practices, making it harder than in earlier days to confront those intent on perpetuating disinformation that can be quite harmful to those on the receiving end. A case in point is the use of historical revisionism, in any form conceivable, to minimize the accomplishments of an individual or a group of individuals; a not uncommon practice when it comes to the affect it has on women and minorities. Solving just this one part of the problem, itself, is indeed a challenge that can only be totally addressed at large.

One seemingly small event can change everything, for better or worse, because everything is somehow related to everything else. When the most powerful and influential leaders and organizations in the world make it possible for women to hold the highest positions (not “almost” the highest) in their organizations equal (not “almost” equal) to what is available to men, we all benefit, including the leaders and organizations themselves. When large corporations refuse to conduct business with and within countries who do not allow women to have the same rights as men, we all benefit. The more all of us work to uncover discriminatory practices and the more those in power promote non-discriminatory practices as being a positive thing, the more we all benefit.

Margaret Hamilton in an Apollo command module (Credit: NASA)

What most worried you during development of the Apollo software, and how did you and your team solve it?

MHH: The greatest challenge was that our software had to be man-rated; which meant lives were at stake. Failure was not an option. Not only did it have to work; it had to work the first time. Not only did the software, itself, have to be ultra-reliable, but the software would need to be able to detect an error and recover from it in real time. It did not disappoint.

The task at hand included developing and integrating all of the software for the command module, the lunar module and the systems software shared between, and residing within, both the command and lunar module; making sure that everything would play together and that there were no integration, communication, or interface conflicts (i.e., data, timing or priority conflicts). Updates, submitted from hundreds of people, were continuously being made over time and over the many releases for every mission; making sure that the software would successfully interface to, and work together with, all the other systems including the hardware, peopleware and missionware.

Because of the never-ending focus on making everything as perfect as possible, anything to do with the prevention of errors was not only not off the table, but it was top priority both during development and during real-time where it was necessary to have the flexibility to be able to detect anything unexpected and recover from it at any time in a real mission. To meet the challenge, the software was developed with an ongoing, overarching focus on finding ways to capitalize on the asynchronous and distributed functionality of the system at large in order to perfect the more systems-oriented aspects of the flight software. Such was the case with the flight software’s system-wide snapshot rollback capabilities and priority displays together with its man-in-the-loop techniques. Our software was designed to be asynchronous in order to have the flexibility to handle the unpredictable, and in order that higher priority jobs would have the capability to interrupt lower priority jobs, based on events as they happened (especially in the case of an emergency).

Each mission was exciting in its own right, but Apollo 11 was special; we had never landed on the moon before. Just as the astronauts were about to land on the moon, everything was going according to plan until something totally unexpected happened. All of a sudden, the on-board flight computer became overtaxed. The software’s priority displays of 1201 and 1202 alarms interrupted the astronaut’s normal mission displays to warn them that there was an emergency, allowing NASA’s Mission Control to understand what was happening, and alerting the astronauts to place the rendezvous radar switch in the right position. The priority displays gave the astronauts a go/no go decision (to land or not to land).

It quickly became clear that the software was not only informing everyone that there was a hardware-related problem, but that the software was compensating for it. With only minutes to spare, the decision was made to go for the landing. The rest is history. The Apollo 11’s crew became the first humans to walk on the moon, and our software became the first software to land on the moon. An explanation of what happened, and the steps taken by the on-board flight software to “continue on” to landing are briefly described in my letter to the editor, “Computer Got Loaded”, published in the March 1, 1971 issue of Datamation.

The development and deployment of this functionality would not have been possible without an integrated system of systems (and teams) approach to systems reliability and the innovative contributions made by the other groups to support our systems-software team in making this become a reality. The hardware team at MIT changed their hardware and the mission planning team in Houston changed their astronaut procedures, both working closely with us to accommodate the priority displays for both the command and lunar modules for any kind of emergency and throughout any mission. In addition, the people at Mission Control were well prepared to know what to do should the astronauts be interrupted with the priority displays.

Since it was not possible (certainly not practical) on Apollo for us to test the software “before the fact” by flying an actual mission, it was necessary for us to test our software by developing a mix of hardware and digital simulations of every (and all aspects of an) Apollo mission which included man-in-the-loop simulations (with real or simulated human interaction); and variations of real or simulated hardware and their integration.

Astronauts who have walked on the moon often describe a certain listlessness once they get home. As an engineer key to that achievement, are you left with a similar feeling? What sort of feeling follows?

MHH: Of course, I would be hard put to even begin to compare feelings of my own to that of an astronaut who walked on the moon! Do you mean by a certain listlessness that I may have experienced a letdown or feeling of depression, because of the fact that nothing could ever follow that could be as exciting? I do not remember a time, following a major event (like landing on the moon) or a major project (like Apollo), when there was a real chance (or when I took a chance) to reminisce and miss the action. There was always something happening immediately thereafter that seemed to be exciting in its own right.

I have always been more “wrapped up” than not, with wasting little time in capturing lessons learned from an experience and doing something about it so that we could apply that knowledge on the adventures to follow. Towards this end, I have found that it helps to focus on learning from the past, not living in it. There was always an adventure to follow that would have its own kind of excitement. I do want to say, however, that what we have been doing over the years with our computer science-related work is much more exciting because of the lessons we learned from Apollo.

Describe your work on Skylab and the space shuttle.

MHH: Skylab was a continuation of the Apollo command module on-board flight software, with new software added for new Skylab requirements. We defined systems software requirements for the Skylab and the Space Shuttle on-board flight software as a result of many of the lessons we had learned from Apollo. Among other things, we performed an empirical study of the Apollo on-board flight software development effort, resulting in formalizing lessons learned. Part of the requirements for Skylab and the Space Shuttle originated from this work.

As a pioneer in the field, what would you say is your greatest contribution to the discipline of computer science?

MHH: For whatever success I have experienced in my work, the credit goes not only to those I have learned so much from and have worked with, but also to the errors I have had the opportunity of having had some responsibility in making, without which we would not have been able to learn the things we did — some with great drama and fanfare, and often with a large enough audience to not want such a thing to ever to happen again!

Having been through some amazing experiences such as those involved with the Apollo on-board flight software, one could not help but do something about learning from them. With initial funding from NASA and the Department of Defense (including the Air Force, the Navy, and the Army), we performed an empirical study of the Apollo effort. This resulted in a systems theory, based upon a concept of control, that has continued to evolve based on lessons learned from Apollo and later projects. From its axioms, we derived a universal systems language together with its automation and its preventative development paradigm.

Margaret Hamilton poses with an MIT pennant inside an Apollo lunar capsule model. (Credit: MIT Museum)

We continue to discover new properties in systems defined with this language. Among other things, we learned that with the use of the language there are no interface errors in a system definition and its derivatives (one of which is its software); and integration within a definition, and from systems to software, is inherent. Along the way, it became clear one day that the root problem with traditional approaches is that they support users in “fixing up wrong things” rather than in “doing things in the right way in the first place.” With a preventative paradigm, instead of looking for more ways to test for errors, and continuing to test for errors late into the life cycle, the majority of errors including all interface errors are not allowed into a system in the first place, just by the way it is defined. Testing for non-existent errors becomes an obsolete endeavor. For each new property discovered, that, in essence, “comes along for the ride,” there is the realization of something (e.g., testing for interface errors) that will no longer be necessary as part of the system’s own development process.

Margaret and the Moon: How Margaret Hamilton Saved the First Lunar Landing was written by Dean Robbins and illustrated by Lucy Knisley. It is available in bookstores everywhere.

How a Small NASA Mission Might Change the Course of Space Exploration

Resource Prospector rover ( NASA Advanced Exploration Systems )

When explorers roamed the New World, they didn’t set foot on uncharted lands and unload from their ships lumber and food. They didn’t send for armadas back home, asking for fresh supplies to stay well fed and in warm beds. Rather, settlement required the necessities of life to be hewn or harvested, and what they unloaded from ships were tools and seed. It was called the Age of Discovery, but it was as well the age of cultivation, the age of construction, the age of contrivance, and, yes, the age of conquest.

We live today in the New Age of Discovery, with explorers like Alan Stern and Lindy Elkins in the roles of James Cook or Bartolomé, and New Horizons and Psyche are our plucky robotic vessels pressing forth into the unknown. As human spaceflight completes its interim retooling for its own push into the final frontier, the requirements for settlement remain unchanged from centuries gone by. You can’t bring with you everything you will need. Survival in the wilderness means subsistence farming and dogged resourcefulness. But how do you do that on another planet?

NASA’s working on it, and the first critical step is a project called Resource Prospector. If their plan works, humanity might one day look back on Resource Prospector as the mission that launched a thousand ships and forever changed the course of human exploration.

IN SITU

“The essence of humanity is to be explorers,” says Jacqueline Quinn, “but today we are bound by what we can carry on our backs—meaning what we can put on our rockets and send up. Until we cease that reliance, we will never break free.” It is obscenely expensive to lift things into space. The workhorse rocket used by NASA is the Atlas 5, which costs more than $10,000 per pound to lift something. The math alone renders impossible the dream of long-duration, large crewed exploration missions, let alone permanent ones.

The solution to this problem, Quinn tells me, is a process called in situ resource utilization. ISRU, as it is abbreviated, is the creation of usable commodities from extraterrestrial materials. You don’t fly bricks to the moon. You make them from lunar soil. You don’t fill a lake on Mars with water from Earth. You make it from elements on and in the Martian ground and sky. Need to fuel your spaceship for the ride back to Earth? All you need are carbon and hydrogen and the right machine to make methane. And so on. There’s a sense of daring to ISRU. It is a new kind of space travel. You’re exploring the solar system without taking everything you need. You’re setting stakes on another world with the intention to live off the land.

It makes sense, of course, and it sounds easy, but it’s never actually been done on another world, and is, in fact, very hard. Quinn, who is based from Kennedy Space Center, is the Resource Prospector payload project manager. She has spent the last decade helping to develop ISRU, and Resource Prospector is the outgrowth of those efforts. Its mission is to go to the moon, study the lunar soil, and determine how easily the water within can be accessed. Its heritage traces back to the Lunar Crater Observation and Sensing Satellite mission in 2009, which discovered water in the south polar region of the moon in a permanently shadowed crater—that is, a crater that hasn’t seen sunlight in over a billion years due to the moon’s low tilt angle.

RP, as the team calls Resource Prospector with the sort of familiarity that Luke Skywalker has with R2, is a rover about the size of a golf cart. At a glance, its design suggests Pathfinder—that golden body, those strange wheels, that solar panel roof (though RP’s panels are steepled). The resemblance is fleeting, however, and the rovers are otherwise entirely different, as the massive vertical drill jutting from its core makes clear. This isn’t a robot made for passive observation. It’s not a tourist; it’s a miner, and when it lands, it has work to do. Those wheels (four rather than Pathfinder’s six) don’t just steer. They articulate. It can climb hills covered in soft soil. When RP is stuck in loose material, it can twist and lift its wheels and “army man crawl” to firmer ground. It’ll need that kind of mobility, too, because it’s designed to drive for kilometers across austere and uncharted lunarscape and into those permanently shadowed lands, where no human or robot has gone before.

ONE METER BELOW

The mission will work like this, according to Jim T. Smith, the lead systems engineer for payload on Resource Prospector. As the rover drives across the lunar surface, an onboard neutron spectrometer will collect data on the soil one to two meters in front of the rover, and one meter below the surface. This data will in turn be correlated with data already collected by previous missions to determine the distribution of hydrogen (including H2O ice) and other elements. (Where RP studies the moon at a “human scale,” orbital data has a much poorer resolution of 60 kilometers per pixel.)

“The first instrument we use is almost like a metal detector on a beach—a neutron spectrometer,” says Smith. “As we traverse the surface it is continually counting epithermal neutrons emanating from the moon. When we see the correct signal and we believe we’ve found a good hydrogen source, the rover is equipped with a drill capable of penetrating one meter down into the surface.” The drill can do two things: It can excavate material to the surface for inspection with a near infrared spectrometer. This will determine if there is water ice present or hydroxyl or whatever. The drill can also capture material at precise depths as far down as one meter and deliver it to individual crucibles, which are then heated by an Oxygen & Volatile Extraction Node (OVEN), which is an oven.

Quinn explains that the oven drives off the gasses, which are analyzed by a gas chromatograph mass spectrometer. It will quantify the constituents present. “Remember, we’re in almost perfect vacuum,” she says. “Being able to physically contain water in a mechanical device and get it into a sealed vessel, so those resources don’t sublime is as important as the original detection. The volatiles may be there, but if you can’t get ahold of them and put them in some sort of vessel, then it’s not doing you a whole hell of a lot of good.”

The last step in the process is perhaps the most poetic and will certainly have the greatest resonance with the largest number of people back on Earth. The vapor will be condensed on a cold finger, forming a water droplet, which RP will then image. The picture of a water droplet beamed back to Earth will mark a turning point in human exploration. Scientists will have drilled into another world, pulled up material, and extracted it as something we can use, something we need.

PARADIGM SHIFT

Resource Prospector is a pioneer in the sense that it is an explorer venturing into unknown territory, but also as it relates to the employment of technology. It will be the first NASA robotic mission to drill deeper than seven centimeters into an extraterrestrial body. It will be the first time we’ve driven into a permanently shadowed region on the moon. It will be the first time NASA has operated on a pole of the moon with a very low angle from which to collect sunlight for its panels, and from which to maintain communications back on Earth. It will be the first time humankind has created a usable commodity from raw material on an alien world. And it might prove to be the first mission to really kick off the commercial race to the lunar surface.

”This whole idea of utilizing the moon and its potential local resources to actually enable exploration architectures is the hot topic right now," says Daniel Andrews, the project manager for Resource Prospector at NASA Ames Research Center. “I can't tell you how many times I'm approached at conferences by commercial parties who say ‘I hope you guys really do get the answers you want from RP because I need them for a business plan that we're putting together.’”

Andrews has more than once been approached by entrepreneurs hoping to use lunar soil to make feedstock for 3D printing. “We’re talking concrete building materials,” he says, “including concrete!” Volatile material utilization is also on the agenda of many companies who hope to make water, usable oxygen, rocket fuel, and other things. Andrews foresees a time when companies are dropping ISRU pallets onto the surface of the moon and filling bottles with volatile-derived resources. “These companies would commoditize volatiles making them available to those who wish to buy it, including this space agency and others. This could be the beginning of a whole new paradigm.”

THE FUTURE

If fifteen years from now an astronaut sets foot on Mars, some might well look back and claim that Pathfinder started it all. It wasn’t the first mission on the ground. There were the Viking landers, of course, and a series of orbiters and flybys. Those missions, however, somehow belonged to antiquity, to a time of black and white televisions and the prospect of atomic annihilation in the Cold War. Pathfinder seemed to come out of nowhere—a mission of peace and wonder that captured the collective American imagination not just for Mars, but for all exploration beyond our little blue marble. It was the mission that allowed NASA to marshal its resources with the support of the people footing the bill. If there is a journey to Mars, Pathfinder was the first step.

Thirty years from now, when there is a moon village of scientists and explorers, and a thriving lunar industrial sector actually based on the moon, people might say, “It might have died with Apollo if not for a little robot called RP.” We harnessed the resources on this world to send a four-wheeled miner to another. And when it got there, it, in turn, harnessed resources it found there. It advanced the cycle. And when people saw water—not mysterious slope lineae or promises beneath an ice shell—but the pure stuff that might have flowed from a tap back home, they were ready. Water! That was the thing that made the public decide at last that we can go to other places. That beyond the colossal intellects of scientists and engineers, there’s something else out there to keep us alive—something ethereal and nourishing on a spiritual level: mother nature.